1/*
2 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3 * Licensed under the GPL
4 */
5
6#include <linux/mm.h>
7#include <linux/sched.h>
8#include <linux/uaccess.h>
9#include <linux/regset.h>
10#include <asm/ptrace-abi.h>
11#include <registers.h>
12#include <skas.h>
13
14void arch_switch_to(struct task_struct *to)
15{
16 int err = arch_switch_tls(to);
17 if (!err)
18 return;
19
20 if (err != -EINVAL)
21 printk(KERN_WARNING "arch_switch_tls failed, errno %d, "
22 "not EINVAL\n", -err);
23 else
24 printk(KERN_WARNING "arch_switch_tls failed, errno = EINVAL\n");
25}
26
27/* determines which flags the user has access to. */
28/* 1 = access 0 = no access */
29#define FLAG_MASK 0x00044dd5
30
31static const int reg_offsets[] = {
32 [EBX] = HOST_BX,
33 [ECX] = HOST_CX,
34 [EDX] = HOST_DX,
35 [ESI] = HOST_SI,
36 [EDI] = HOST_DI,
37 [EBP] = HOST_BP,
38 [EAX] = HOST_AX,
39 [DS] = HOST_DS,
40 [ES] = HOST_ES,
41 [FS] = HOST_FS,
42 [GS] = HOST_GS,
43 [EIP] = HOST_IP,
44 [CS] = HOST_CS,
45 [EFL] = HOST_EFLAGS,
46 [UESP] = HOST_SP,
47 [SS] = HOST_SS,
48 [ORIG_EAX] = HOST_ORIG_AX,
49};
50
51int putreg(struct task_struct *child, int regno, unsigned long value)
52{
53 regno >>= 2;
54 switch (regno) {
55 case EBX:
56 case ECX:
57 case EDX:
58 case ESI:
59 case EDI:
60 case EBP:
61 case EAX:
62 case EIP:
63 case UESP:
64 break;
65 case ORIG_EAX:
66 /* Update the syscall number. */
67 UPT_SYSCALL_NR(&child->thread.regs.regs) = value;
68 break;
69 case FS:
70 if (value && (value & 3) != 3)
71 return -EIO;
72 break;
73 case GS:
74 if (value && (value & 3) != 3)
75 return -EIO;
76 break;
77 case DS:
78 case ES:
79 if (value && (value & 3) != 3)
80 return -EIO;
81 value &= 0xffff;
82 break;
83 case SS:
84 case CS:
85 if ((value & 3) != 3)
86 return -EIO;
87 value &= 0xffff;
88 break;
89 case EFL:
90 value &= FLAG_MASK;
91 child->thread.regs.regs.gp[HOST_EFLAGS] |= value;
92 return 0;
93 default :
94 panic(fmt: "Bad register in putreg() : %d\n", regno);
95 }
96 child->thread.regs.regs.gp[reg_offsets[regno]] = value;
97 return 0;
98}
99
100int poke_user(struct task_struct *child, long addr, long data)
101{
102 if ((addr & 3) || addr < 0)
103 return -EIO;
104
105 if (addr < MAX_REG_OFFSET)
106 return putreg(child, regno: addr, value: data);
107 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
108 (addr <= offsetof(struct user, u_debugreg[7]))) {
109 addr -= offsetof(struct user, u_debugreg[0]);
110 addr = addr >> 2;
111 if ((addr == 4) || (addr == 5))
112 return -EIO;
113 child->thread.arch.debugregs[addr] = data;
114 return 0;
115 }
116 return -EIO;
117}
118
119unsigned long getreg(struct task_struct *child, int regno)
120{
121 unsigned long mask = ~0UL;
122
123 regno >>= 2;
124 switch (regno) {
125 case FS:
126 case GS:
127 case DS:
128 case ES:
129 case SS:
130 case CS:
131 mask = 0xffff;
132 break;
133 case EIP:
134 case UESP:
135 case EAX:
136 case EBX:
137 case ECX:
138 case EDX:
139 case ESI:
140 case EDI:
141 case EBP:
142 case EFL:
143 case ORIG_EAX:
144 break;
145 default:
146 panic(fmt: "Bad register in getreg() : %d\n", regno);
147 }
148 return mask & child->thread.regs.regs.gp[reg_offsets[regno]];
149}
150
151/* read the word at location addr in the USER area. */
152int peek_user(struct task_struct *child, long addr, long data)
153{
154 unsigned long tmp;
155
156 if ((addr & 3) || addr < 0)
157 return -EIO;
158
159 tmp = 0; /* Default return condition */
160 if (addr < MAX_REG_OFFSET) {
161 tmp = getreg(child, regno: addr);
162 }
163 else if ((addr >= offsetof(struct user, u_debugreg[0])) &&
164 (addr <= offsetof(struct user, u_debugreg[7]))) {
165 addr -= offsetof(struct user, u_debugreg[0]);
166 addr = addr >> 2;
167 tmp = child->thread.arch.debugregs[addr];
168 }
169 return put_user(tmp, (unsigned long __user *) data);
170}
171
172long subarch_ptrace(struct task_struct *child, long request,
173 unsigned long addr, unsigned long data)
174{
175 int ret = -EIO;
176 void __user *datap = (void __user *) data;
177 switch (request) {
178 case PTRACE_GETFPREGS: /* Get the child FPU state. */
179 return copy_regset_to_user(child, task_user_regset_view(child),
180 REGSET_FP_LEGACY,
181 0, sizeof(struct user_i387_struct),
182 datap);
183 case PTRACE_SETFPREGS: /* Set the child FPU state. */
184 return copy_regset_from_user(child, task_user_regset_view(child),
185 REGSET_FP_LEGACY,
186 0, sizeof(struct user_i387_struct),
187 datap);
188 case PTRACE_GETFPXREGS: /* Get the child FPU state. */
189 return copy_regset_to_user(child, task_user_regset_view(child),
190 REGSET_FP,
191 0, sizeof(struct user_fxsr_struct),
192 datap);
193 case PTRACE_SETFPXREGS: /* Set the child FPU state. */
194 return copy_regset_from_user(child, task_user_regset_view(child),
195 REGSET_FP,
196 0, sizeof(struct user_fxsr_struct),
197 datap);
198 default:
199 ret = -EIO;
200 }
201 return ret;
202}
203

source code of linux/arch/x86/um/ptrace_32.c